A system is provided comprising a plurality of instant messaging client applications (202, 207, 208, 209) communicating via a computer network (206) to send and receive messages in real time integrated with n-way teleconferencing capability via a telephone network (216). The system includes a plurality of instant messaging client applications (202, 207, 208, 209), an instant messaging server (204), and a teleconferencing server (210), all connected via a computer network (206). The teleconferencing server (210) enables n-way telephone connections via the telephone network (216). The n-way telephone connections are provided to telephone apparatus of at least some users of the instant messaging client applications who can visualise the teleconference via a graphical user interface (600) of the instant messaging client application.